Evolution and function of B chromosome 45S rDNA sequences in Brachycome dichromosomatica

Genome ◽  
2007 ◽  
Vol 50 (7) ◽  
pp. 638-644 ◽  
Author(s):  
Sylvia Marschner ◽  
Armin Meister ◽  
Frank R. Blattner ◽  
Andreas Houben
Keyword(s):  
Phylogenetic Analysis ◽  
Internal Transcribed Spacer ◽  
B Chromosome ◽  
Its2 Sequence ◽  
B Chromosomes ◽  
Rrna Gene ◽  
45S Rdna ◽  
Internal Transcribed Spacer 2 ◽  
Rdna Sequences ◽  
And Function

The origin and activity of 45S rDNA located on micro B chromosomes of the daisy Brachycome dichromosomatica were analysed. The internal transcribed spacer 2 (ITS2) of the 45S rRNA gene was sequenced for micro B, large B, and A chromosomes of B. dichromosomatica cytodeme A2, and conserved differences were identified between sequences originating from A and both types of B chromosomes. Phylogenetic analysis did not identify a species containing an ITS2 sequence more similar to either of the B chromosome sequences than the B. dichromosomatica A chromosome sequences. Thus, an origin of the B chromosomes from A chromosomes at a time prior to the divergence of the 4 cytodemes of B. dichromosomatica is suggested. The frequent (70%) nucleolar non-association of micro B chromosomes suggests inactivity of micro B 45S rDNA.

scholarly journals The new Internal Transcribed Spacer 2 diagnostic tool clarifies the taxonomic position and geographic distribution of the North American malaria vector Anopheles punctipennis

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
James M. Hodge ◽  
Andrey A. Yurchenko ◽  
Dmitriy A. Karagodin ◽  
Reem A. Masri ◽  
Ryan C. Smith ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Internal Transcribed Spacer ◽  
Single Species ◽  
Its2 Sequence ◽  
Pathogen Transmission ◽  
Molecular Diagnostic ◽  
Diagnostic Tools ◽  
Sequence Length ◽  
Phylogenetic Position ◽  
Internal Transcribed Spacer 2

Abstract Background The malaria mosquito Anopheles punctipennis, a widely distributed species in North America, is capable of transmitting human malaria and is actively involved in the transmission of the ungulate malaria parasite Plasmodium odocoilei. However, molecular diagnostic tools based on Internal Transcribed Spacer 2 (ITS2) of ribosomal DNA are lacking for this species. Anopheles punctipennis is a former member of the Anopheles maculipennis complex but its systematic position remains unclear. Methods In this study, ITS2 sequences were obtained from 276 An. punctipennis specimens collected in the eastern and midwestern United States and a simple and robust Restriction Fragment Length Polymorphism approach for species identification was developed. The maximum-likelihood phylogenetic tree was constructed based on ITS2 sequences available through this study and from GenBank for 20 species of Anopheles. Results The analysis demonstrated a consistent ITS2 sequence length and showed no indications of intragenomic variation among the samples based on ITS2, suggesting that An. punctipennis represents a single species in the studied geographic locations. In this study, An. punctipennis was found in urban, rural, and forest settings, suggesting its potential broad role in pathogen transmission. Phylogeny based on ITS2 sequence comparison demonstrated the close relationship of this species with other members of the Maculipennis group. Conclusions This study developed molecular tools based on ITS2 sequences for the malaria vector An. punctipennis and clarified the phylogenetic position of the species within the Maculipennis group.

The 5S rRNA gene units in ancestral two-rowed barley (Hordeum spontaneum C. Koch) and bulbous barley (H. bulbosum L.): sequence analysis and phylogenetic relationships with the 5S rDNA units of cultivated barley (H. vulgare L.)

Genome ◽  
1996 ◽  
Vol 39 (1) ◽  
pp. 140-149 ◽  
Author(s):  
Bernard R. Baum ◽  
Douglas A. Johnson
Keyword(s):  
Phylogenetic Analysis ◽  
5S Rdna ◽  
Hordeum Spontaneum ◽  
Wild Relatives ◽  
5S Rrna ◽  
Rrna Genes ◽  
Rrna Gene ◽  
Sequence Comparisons ◽  
Rdna Sequences ◽  
Cultivated Barley

5S rRNA genes from several accessions of Hordeum spontaneum and Hordeum bulbosum, wild relatives of cultivated barley, Hordeum vulgare, have been amplified by the polymerase chain reaction, cloned, and sequenced. Evaluation of aligned sequences along with principal coordinate analysis demonstrates that the two classes of 5S rDNA sequences found in cultivated barley, and subclasses (groups) of these sequences, can also be found in its closest wild relatives. The two classes of units, formerly categorized as containing short or long 5S rDNA repeats, are distinguishable by the presence or absence of a TAG repeating unit. Sequence comparisons of individual clones (units) isolated from different species have allowed us to confirm that orthology exists for several groups. This demonstration of orthologous groups suggests that the 5S rDNA sequence may be useful for further phylogenetic analysis in the genus Hordeum and possibly in the Triticeae. Key words : 5S rDNA, barley, sequence diversity, phylogenetic analysis.

scholarly journals Low internal transcribed spacer rDNA variation in New Zealand Bonamia ostreae: evidence for a recent arrival

2020 ◽  
Vol 139 ◽  
pp. 121-130 ◽  
Author(s):  
HS Lane ◽  
JB Jones
Keyword(s):  
New Zealand ◽  
Northern Hemisphere ◽  
Internal Transcribed Spacer ◽  
18S Rrna Gene ◽  
Its Rdna ◽  
Rrna Gene ◽  
Rdna Sequences ◽  
Rdna Variation ◽  
Bonamia Ostreae ◽  
High Level

Bonamia ostreae is a haplosporidian parasite of oysters that was first reported to occur in the Southern Hemisphere in 2015 in the New Zealand flat oyster Ostrea chilensis. Until that report, B. ostreae had been restricted to populations of O. edulis within the Northern Hemisphere. This large range extension raised questions regarding B. ostreae dispersal, including whether B. ostreae is a recent introduction and from where it originated. The whole 18S rRNA gene of New Zealand B. ostreae revealed 99.9-100% sequence homology to other published B. ostreae 18S rDNA sequences. Internal transcribed spacer (ITS) rDNA sequences (n = 29) were generated from New Zealand B. ostreae and compared to published B. ostreae sequences from 3 Northern Hemisphere sites: California, USA (n = 18), Maine, USA (n = 7), and the Netherlands (n = 6) to investigate intraspecific variation. Low ITS rDNA variation was observed from New Zealand B. ostreae isolates, and high levels of variation were observed from Northern Hemisphere B. ostreae sequences. We hypothesise that the low ITS rDNA diversity found in New Zealand B. ostreae is the result of a founder effect resulting from a single introduction from a limited number of propagules. The high level of ITS rDNA variation from the Northern Hemisphere prevented inferences of dispersal origins. New Zealand B. ostreae were genetically differentiated from all sites, and additional genetic data are required to better determine the origin of B. ostreae in New Zealand.

scholarly journals Internal Transcribed Spacer Regions of rRNA Genes of Pneumocystis carinii from Monkeys

2001 ◽  
Vol 8 (3) ◽  
pp. 503-508 ◽  
Author(s):  
John Y. C. Hsueh ◽  
Rudolf P. Bohm ◽  
Peter J. Didier ◽  
Xing Tang ◽  
Mark E. Lasbury ◽  
...  
Keyword(s):  
Internal Transcribed Spacer ◽  
Pneumocystis Carinii ◽  
Distinct Species ◽  
Its2 Sequence ◽  
Rrna Genes ◽  
Its2 Region ◽  
Rrna Gene ◽  
5.8S Rrna Gene ◽  
Sequence Variations ◽  
5.8S Rrna

ABSTRACT Analysis of sequence variations among isolates ofPneumocystis carinii f. sp. macacae from 14 Indian rhesus monkeys (Macaca mulatta) at the internal transcribed spacer (ITS) regions of the nuclear rRNA gene was undertaken. Like those from P. carinii f. sp.hominis, the ITS sequences from various P. carinii f. sp. macacae isolates were not identical. Two major types of sequences were found. One type of sequence was shared by 13 isolates. These 13 sequences were homologous but not identical. Variations were found at 13 of the 180 positions in the ITS1 region and 28 of the 221 positions in the ITS2 region. These sequence variations were not random but exhibited definite patterns when the sequences were aligned. According to this sequence variation, ITS1 sequences were classified into three types and ITS2 sequences were classified into five types. The remaining specimen had ITS1 and ITS2 sequences substantially different from the others. Although some specimens had the same ITS1 or ITS2 sequence, all 14 samples exhibited a unique whole ITS sequence (ITS1 plus ITS2). The 5.8S rRNA gene sequences were also analyzed, and only two types of sequences that differ by only one base were found. Unlike P. carinii f. sp. hominis infections in humans, none of the monkey lung specimens examined in this study were found to be infected by more than one type of P. carinii f. sp. macacae. These results offer insights into the genetic differences between P. carinii organisms which infect distinct species.

scholarly journals Internal transcribed spacer based identification of Aspergillus fumigatus isolated from poultry feed samples

2017 ◽  
Vol 4 (3) ◽  
pp. 165-171
Author(s):  
Md Muket Mahmud ◽  
Jayedul Hassan ◽  
KHM Nazmul Hussain Nazir
Keyword(s):  
Phylogenetic Analysis ◽  
Aspergillus Fumigatus ◽  
Internal Transcribed Spacer ◽  
Molecular Techniques ◽  
Rrna Genes ◽  
Poultry Feed ◽  
Rrna Gene ◽  
28S Rrna ◽  
Its Regions ◽  
Feed Samples

Among over 180 Aspergilli, Aspergillus fumigatus is the most common etiological agent causing invasive mold infection mostly in immunocompromised human and animal. Besides, the fungus is used for various useful purposes. However, for the utilization of A. fumigatus as a useful candidate, accurate identification is crucial. Here, the research work was aimed at identifying A. fumigatus from poultry feed samples using conventional and molecular techniques. Out of 23 feed samples, 2 (8.7%) were found to be positive for A. fumigatus. The internal transcribed spacer 1 (ITS 1) and ITS 2 regions and the 5.8S ribosomal DNA (rDNA) region of the fungus were amplified by polymerase chain reaction. The ITS regions are located between the 18S and 28S rRNA genes, and rRNA gene for 5.8S RNA separates these two ITS regions. The isolated gene has been sequenced and deposited in the GenBank (accession no. KC142152). The gene was 100% similar to other reference species of A. fumigatus, whereas in phylogenetic analysis, a clear distance was found in the cases of other Aspergilli. Based on the unique nature of the ITS1 and ITS2 regions and phylogenetic analysis of the genes, A. fumigatus was correctly identified. The isolated strain could be a good candidate for further studies especially for utilization in the field of biotechnology.Res. Agric. Livest. Fish.4(3): 165-171, December 2017

Placozoa: at least two

Biologia ◽  
2007 ◽  
Vol 62 (6) ◽  
Author(s):  
Matthias Wolf ◽  
Christian Selig ◽  
Tobias Müller ◽  
Nicole Philippi ◽  
Thomas Dandekar ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Internal Transcribed Spacer ◽  
Distinct Species ◽  
Secondary Structures ◽  
Its2 Sequence ◽  
Structure Alignment ◽  
Sequence Structure ◽  
Rna Sequence ◽  
Internal Transcribed Spacer 2 ◽  
Compensatory Base Changes

AbstractIt was shown that compensatory base changes (CBCs) in internal transcribed spacer 2 (ITS2) sequence-structure alignments can be used for distinguishing species. Using the ITS2 Database in combination with 4SALE — a tool for synchronous RNA sequence and secondary structure alignment and editing — in this study we present an in-depth CBC analysis for placozoan ITS2 sequences and their respective secondary structures. This analysis indicates at least two distinct species in Trichoplax (Placozoa) supporting a recently suggested hypothesis, that Placozoa is “no longer a phylum of one”.

Orthopodomyia pulcripalpis (Diptera: Culicidae), a genus and species new to the Iranian mosquito fauna, with a review of bionomical information*

Zootaxa ◽  
2017 ◽  
Vol 4299 (1) ◽  
pp. 141 ◽  
Author(s):  
SHAHYAD AZARI-HAMIDIAN ◽  
BEHZAD NOROUZI ◽  
AYOOB NOORALLAHI
Keyword(s):  
New Species ◽  
Aedes Albopictus ◽  
Internal Transcribed Spacer ◽  
Sequence Data ◽  
Its2 Sequence ◽  
Internal Transcribed Spacer 2 ◽  
As Species ◽  
Southwestern Iran ◽  
A New Species

The most recent checklist of Iranian mosquitoes (Diptera: Culicidae) includes 64 species representing seven genera (Azari-Hamidian, 2007; Azari-Hamidian & Harbach, 2009). Subsequently, Oshaghi et al. (2008) found that Anopheles superpictus Grassi is two species in Iran based on the Internal Transcribed Spacer 2 (ITS2) sequences of rDNA, which were later listed as species A and B by Harbach (2013), and Djadid et al. (2009) recognized a new species of the Anopheles hyrcanus group (An. hyrcanus spIR) from southwestern Iran, also based on ITS2 sequence data. More recently, Doosti et al. (2016) reported the occurrence of Aedes albopictus (Skuse) in southeastern Iran. 

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